Search results for " gasification"

Corrosion Resistance of Alloys in IGCC Environment

2001

IGCC recovery boiler materials are subject to severe corrosion in environments composed of a gas mixture (CO-H 2 -H 2 O-CO 2 -H 2 S) and vanadium-containing fly-ash resulting from the combustion of oil residues. This paper presents a study of the corrosion behaviour of two Fe-Ni-Cr austenitic alloys in a typical IGCC environment at 400°C. The alloy composition influences the vanadium incorporated in the corrosion scales during the test, which affects the scale growth process. The valence state (determined by micro-XANES) and the amount of the incorporated vanadium is modified by a subsequent air flow at 400°C.

Experimental and fluid dynamic study of continuous supercritical water gasification of glucose

2016

Abstract The supercritical water gasification (SCWG) of glucose as a model compound for H 2 production is studied in term of process development at 25 MPa and 650 °C. Gasification has been investigated using a laboratory scale continuous plant comprising a continuous down flow reactor with a volume of 200 cm 3 , a heat recovery section and pre-heat of the biomass to simulate more closely an industrial design. Feed streams (pure water and glucose solution) are introduced at the top of the vessel and products are extracted from the bottom. The reactor is equipped with various inlet points that allow to modify the inlet position of reacting streams in order to study the effect of stream mixing…

Numerical and Experimental Investigation of Equivalence Ratio (ER) and Feedstock Particle Size on Birchwood Gasification

2017

This paper discusses the characteristics of Birchwood gasification using the simulated results of a Computational Fluid Dynamics (CFD) model. The CFD model is developed and validated with the experimental results obtained with the fixed bed downdraft gasifier available at the University of Agder (UIA), Norway. In this work, several parameters are examined and given importance, such as producer gas yield, syngas composition, lower heating value (LHV), and cold gas efficiency (CGE) of the syngas. The behavior of the parameters mentioned above is examined by varying the biomass particle size. The diameters of the two biomass particles are 11.5 mm and 9.18 mm. All the parameters investigate wit…

Correction to Overview and Essentials of Biomass Gasification Technologies and Their Catalytic Cleaning Methods

2017

Nature of water-biochar interface interactions

2012

A poplar biochar obtained by an industrial gasification process was saturated with water and analyzed using fast field cycling (FFC) NMR relaxometry in a temperature range between 299 and 353 K. Results revealed that the longitudinal relaxation rate increased with the increment of the temperature. This behavior was consistent with that already observed for paramagnetic inorganic porous media for which two different relaxation mechanisms can be accounted for: outer- and inner-sphere mechanisms. The former is due to water diffusing from the closest approach distance to infinity, whereas the second is due to water interacting by nonconventional H-bonds to the porous surface of the solid materi…

A model of biomass char gasification describing the change in catalytic activity of ash

2012

A comprehensive description of catalytic effects during char gasification under various conditions relevant to biomass gasification was made. A three-parallel reaction model was proposed to describe the dynamic change in catalytic activity of ash during gasification of biomass char particles. Three different regimes of conversion were identified by analyzing char reactivity experiments conducted in a vertical TGA with nine biomasses under a wide range of operating conditions (temperature: 1023–1123 K, pressure: 0.1–3.0 MPa and gasification mixtures of CO2–CO–H2O–H2): (1) catalytic char gasification with deactivation of catalyst, (2) non-catalytic char gasification, and (3) catalytic char ga…

Improvement of Biomass Gasification/Combustion Characteristics by Microwave Pretreatment of Biomass Pellets

2021

Supercritical water gasification of waste oils as a source of syngas

2021

A huge amount of waste oil is produced worldwide. Also substantial amount of virgin oils is available that are interesting candidates for upgrading into syngas. Supercritical water gasification (SCWG) can be considered as an aqueous phase reforming process to produce syngas from oils. In this work, a variety of waste and virgin oils were gasified in a continuous down-flow autoclave reactor at supercritical conditions. Experiments were carried out at 430 °C and 660 °C, 25 MPa, with a residence time in the range 103-170 s, in order to investigate gasification and carbon efficiency, hydrogen yield and composition of the produced gas. All the analysed feedstocks were suspended in water at vario…

Combined Oxidation-Gasification system for waste treatment with supercritical water: LCA and performance analysis

2020

In this study the environmental performance of a first of a kind integrated process based on supercritical water gasification and supercritical water oxidation, was evaluated using Life Cycle Assessment (LCA). The process was applied to the treatment of carbon black and used oil as model waste. Mass and energy balances were performed using Aspen Plus, and the environmental assessment was carried out through SimaPro. For the analysis was chosen a “From cradle to grave” approach, considering impact categories like climate change, ozone depletion, human toxicity, particulate matter, land use, resource depletion and others relevant indicators. The environmental profile of SCW-GcO process was co…

Fluidized Bed Combustion and Gasification of Fossil and Renewable Slurry Fuels

2021

This article provides a comprehensive review of the state of the art and more recent developments of the thermochemical treatments of slurry fuels in fluidized beds (FB). The review focuses on FB combustion and gasification of slurry fuels based on coal, biomass, sludge, and wastes from industry, agriculture, and the civil sector. The investigations at research and industrial levels over the last decades are presented and discussed, highlighting the adopted technological solutions, the results in terms of feasibility and efficiency, and the perspectives of future development. The different behavior between bubbling and circulating beds was addressed, in particular the optimal choice dependi…